Method of manufacturing surgeons&#39; needles



1952 J. J. KOHUT METHOD OF MANUFACTURING SURGEONS NEEDLES Filed March 3,1950 INVENTOR cfamvcl/ionur fli- ATTORNEYS Patented Dec. 2, 1952 METHODOF MANUFACTURING SURGEONS NEEDLES John J. Kohut, New Brunswick, N. J.,assignor to The Loyal T. Ives Company, Inc., New Brunswick, N. J., acorporation of New Jersey Application March 3, 1950, Serial No. 147,521

2 Claims.

The present invention relates to the production of surgeons needles andthe like of the type wherein a suture is received and held within anaxial bore formed in the shank end of the needle. It is an object ofthis invention to provide an improved procedure for the manufacture ofsuch needles, and more particularly to improve the procedure disclosedand claimed in Patent No. 2,411,079 granted to G. H. J. Baule onNovember 12, 1946.

The general requirements of surgeons needles are well known and do notrequire restatement herein. The production of such needles presentsseveral manufacturing difficulties due principally to the smalldiameters of the needles which may range from .010 to .060 of an inch,and the requirement that the suture be securely attached withoutsubstantial enlargement of the needle shank. The finished needledescribed in the Baule patent is admirably suited for use by surgeonsbut the production thereof as described in said patent is attended withcertain difliculties. For example, the expanding of the shank end of theneedle has a tendency to harden the metal of that end and render thesubsequent drilling operation more difficult than it otherwise would be.Moreover, the engagement of the needle shank by suitable dies during theenlarging operation is apt to mar the surface in an undesirable manner.It is also difilcult to cause the metal to flow evenly during theenlarging operation, with the result that the axial bore may not beproperly centered and the surrounding walls may not be of uniformthickness. Furthermore the enlarging operation is not easily carried outupon automatic machines which must be employed in the manufacture ofthese needles in order that they may be produced at an economical price.

With the foregoing and other considerations in mind the presentprocedure has been invented whereby the basic operations can be carriedout largely upon automatic machinery to produce needles of this type inan eflicient and economical manner.

The invention will be described in connection with the accompanyingdrawings wherein Figure 1 illustrates a surgeons needle with at tachedsuture which may be produced according to the present invention, theshank end being partially sectionalized to show the interiorconstruction;

Figures 2 and 3 are partially sectionalized views of the shank end ofthe needle of Figure 1 illustrating two steps in the production thereof;

Figure 4 is a partially sectionalized view of the needle of Figure 1illustrating another step in the production thereof;

Figure 5 illustrates a modification of the procedure illustrated inFigure 4;

Figures 6 and 7 illustrate additional steps which may be performed ifdesired; and

Figure 8 illustrates the step of securing a suture to a needle shank.

Referring to the drawings it will be seen that a needle I has a pointedend 2 and a shank end 3. The shank end 3 has an axial bore 4 which, inthe finished needle, is of less diameter in the neighborhood of its openend than at its inner or closed end. A suture 5 has its end lying in thebore 4 and is engaged firmly by the constricted portion 6 thereof, thussecurely attaching the suture to the needle. Such a needle is shown inthe Baule patent, but although the resulting structure is substantiallythe same the method of producing it in accordance with the presentinvention is different as will hereinafter appear.

The procedure about to be described starts with the selection of wirehavin the desired composition. The diameter of the selected wire shouldbe slightly greater than that of the finished needle while the lengthmay be suflicient to make a number of needles. For example, a wire of.0255 or .0250 of an inch in diameter may be used to produce a needlehaving a finished diameter of .022 of an inch.

The end I of such a length of wire after it has been straightened maythen be faced and centered as shown in Figure 2. This may beaccomplished by chucking the wire in a suitable lathe, preferably anautomatic lathe. The next operation, as illustrated in Figure 3,consists of drilling the hole 4 in the shank end as by bringing asuitable drill into alignment with the wire while still held in thechuck used for the first operation. Either the chuck or the drill orboth may be rotated. The diameter of the drilled hole will, of course,be selected with relation to the size of wire used, and the diameter ofthe suture ultimately to be inserted therein. For example, in the caseof a finished needle of .022 of an inch in diameter, the diameter of thehole should be about .006 of an inch to accommodate a suture of about.005 of an inch in diameter. The depth of the hole will vary withdifferent sizes of suture but generally a depth of a: or 1 's of an inchwill be satisfactory.

The end of the wire is now released from the chuck and advanced so thata length of wire slightly longer than the desired length of the finishedneedle is exposed, whereupon the chuck is again engaged with the wire. Acenter 8 may be moved into engagement with the outer end of the wire asindicated in Figure 4. An appropriate cutting tool is now brought intoengagement with the wire at a point slightly removed from the shank end3, the wire is rotated and the cutting tool is fed along the wire fromright to left in order to reduce the diameter by about .003 to .0035 ofan inch until the region of the pointed end is reached, whereupon thecutting tool is gradually fed forward to form the pointed end 2 and tosever the needle from the wire la remaining in the chuck.

The purpose and effect of this operation is to form a needle with ashank end 3 of larger diameter than the major portion of the needle andof a more limited extent longitudinally of the needle than the depth ofthe suture receiving hole l.

A modified procedure includes the reduction of the needle wire for themajor portion of its length by a swaging operation. For such an operation a piece of wire of sufficient length to make one or two needlesmay be selected. If the two needle length is preferred, first one endand then the other may be presented to a s'waging machine so as to leavea mid portion of the original diameter as indicated in Figure 5, or thetwoneedle length can be swaged simultaneously on 'bothends. If a Singleneedle length is used an unreducediportion will be left at one end. Bythis swaging operation the diameter of the wire will'be reduced to anextent similar to the reduction described with respect to the turningoperation. Thereafter, if the twc needle length is used, the wire may becut along the dotted line of Figure 5 and each outer end may be pointedto form 'a pointed needle blank, or the pointing operationmay be donebefore cutting the blank into two .parts. If a single needle length isused it may be pointed after the reducing operation. Each need-1e blank,however obtained, may then be chucked for facing and drilling inthemanner shown and described in connection with Figures 22nd '3, thedifference being that the unreduced shank end 3 has already been formedon the needle wire and the turning down indicated in Figure 4 has becomeunnecessary.

If desired, the inner wall of the axial recess t may be roughened toincrease the security of the engagement with the suture. ted by theformation of internal threads El as indicated in Figure 5. A tappingoperation to form these threads could advantageously be performedimmediately following the drilling of the axial recess t as abovedescribed. Another roughening of the inner wall of the axial recess bymeans of nibs lilis illustrated in Figure 7. At the appropriate stage inthe production of the needle, as for example after the axial recess thas been formed and the diameter of the needie wire reduced thus leavingan enlarged shank end, a mandrel II having recesses :2 may be insertedin the axial recess 4 and'external pressure applied by two die blocks ofthe type illustrated-in Figure 8, to cause the metal of the shank end tofiow into the recesses 52 and form the nibs it.

Needlesproduced in accordance with the ,.prcedure above described mayIce-subjected to the usual finishing operations, such as tempering,final pointing and polishing, and will then be ready for the attachmentof the suture.

As illustrated in Figure .8, the end of the-suture 5 of a diameter tofill the axial recess i is placed therein. The assembled needle andsuture are then brought to a suitable press in which are mounted the twodie blocks l3 and i l. Each oi these blocks has a semi-cylindricalmatinggroov'e of a radius substantially equal to that of the majorportion, that is, the finished portion, of the needle. Pressure exertedby the die blocks on the shank end of the needle will cause the metal ofthe larger shank end to fiow inwardly around the suture therebyproducing the structure shown in Figure 1 wherein the constrictedportion 6 firmly engages the suture 5. If either of the modified formsshown in Figures 6 and 7 is used, the roughened inside wall of the axialrecess 4 will also advantageously engage the end of the suture.

This may be eiiec- I The invention herein described may be variouslymodified within the scope of the subjoined claims.

I claim my invention:

1. The improvement in the art of making surgical needles of the typewherein the suture is engaged by the inner walls of an axial cylindricalbore at the shank end, which improvement consists in selecting a lengthof needle Wire having a greater diameter than that desired for anyportion of the finished needle, reducing the needle to a diameter lessthan the original diameter of the wire throughout the length of theneedle except for a limited portion at theshank end thereof boring asuture receiving hole axially to adepth greater than the longitudinalextentiof the unreduc'ed portion-inserting a recessed inandrel in theaxial-bore, forming suture engaging nibs projecting from the inner wallof 'theaxial bore by pressing the'unreduced shank end "about the mandrelwith a force that causes metal :of the wall of the bore to flow intorecesses :inith'e mandrel, and leaving the unreduced shank :end

with its diameter larger than the diameterro'f the rest of the needleafter the nib forming step thereby provi ing areiatively large.shanke'nd portion which after insertion of a suture inlthe axial boretoa distance exceeding the length of said endportion may be contractedabout .a portion of the suture spaced from the inner end thereof tosecurely "attach the suture to the needie.

2. In the art of making surgical needles with the suture attached to theneedle, the improvement which comprises providing 'a length'of neediewire having a. diameter greater than "that desired for any portion'o'ithe finished needle. boring a suture-receiving hole axially toagpredetermined longitudinal depth, reducingthe needie to a diameterless than the orignal diameter of the wire throughout the length "of theneedle except for a limited portion of the shanlcend thereof, saidlimitedportion having a longitudinal extent substantially less than thelongitudinal depth of the bore, inserting a circumferentially recessedmandrel in the: bore, forming sutureengaging nibs projecting from theinnerwall of the axial bore by-pressing the unre'duced 'sh'ank end aboutthe mandrel with a force that causes the metal of the wallet the boreto-fiow-intoathe recesses in the mandrel, leaving the unreduced shankend with its diameterlarger than thediamet'er of the recess oftheneedle, withdrawing the mandrel, inserting into the axial bore'asuture having-a diameter slightly less thanthe diameter of the bore, andreducing the enlarged en'd of the needle to the same diameter as theadjacent reducedsportion by forcing the metal inward to reduce thediameter of a-portion-of the bore so that the walls of the bore and-the-nibs-firmly grip the suture.

JOHN J. KOHU-T.

REFERENCES CITED The following references are of record inthe file ofthis patent:

UNITED STATES PATENTS Number Name JDa'te 160,238 Sauter Feb. 23, 1875280,682 Smith July 3,:1-8'83i 1,665,216 Morton et al. Apr. 10,19281,830,027 Hayden Nov. 3, 1931 2,411,079

